[The molecular genetic and clinical findings in two probands with Stargardt disease]. / Molekulárne genetická prícina a klinický nález u dvou probandu se Stargardtovou chorobou.

PURPOSE: The aim of our study was to describe the phenotype and to perform molecular genetic investigation in two probands of Czech origin diagnosed with Stargardt disease (STGD). METHODS: Both males underwent ocular examination including assessment by high-resolution spectral domain optical coherence tomography (SD-OCT). DNA was isolated from venous blood. Mutation detection was performed using the ABCA4 genotyping microarray (Asper Ophthalmics, Estonia). RESULTS: The best corrected visual acuity in proband 1 (aged 39 years) was 0.1 bilaterally, and 0.05 in proband 2 (aged 26 years). Fundus examination showed typical multiple yellow-white lesions and macular atrophy. Alterations of retinal pigment epithelium, retinal thinning and disruption of the photoreceptor inner segment ellipsoid band were detected with an SD-OCT. Two known disease-causing mutations in ABCA4 were identified in proband 1; c.4234C>T, p.(Gln1412*) in exon 28; and c.5882G>A, p.(Gly1961Glu) in exon 42. Only one pathogenic change was detected in proband 2; c.1988G>A, p.(Trp663*) in exon 14. A second change, anticipated because of the recessive status of the disease, was not identified. CONCLUSION: The frequency and full spectrum of ABCA4 mutations in Czech patients with inherited retinal disorders is yet to be established. The inability to detect a second pathogenic change in ABCA4 coding sequences in proband 2 warrants further investigation.

[Application of SNP array method in prenatal diagnosis]. / Aplikace metody SNP array v prenatální diagnostice.

OBJECTIVES: SNP array (array method using Single Nucleotide Polymorphisms) enables to detect cytogenetically undetectable submicroscopic alterations (microdeletions, microduplications), which could be also causative for ultrasonographic anomalies of fetus. This article describes the principle, advantages, disadvantages and application possibilities of the SNP array method in prenatal diagnosis. The ten month experience with SNP array use in prenatal diagnosis is presented. DESIGN: Prospective study. SETTINGS: Gennet, Prague. MATERIAL AND METHODS: During the period from April 2010 to January 2011 we performed 110 SNP array analyses of fetal DNA: 14 chorionic villi samples (CVS), 88 amniotic fluid samples (AMC), 1 cord blood sample and 7 miscarriage samples. Laboratory tests were carried out on DNA from both cultured and uncultured fetal cells. Examinations were performed in fetuses with sonographic abnormal findings having normal karyotype. In addition 14 fetal cytogenetic abnormalities were solved. SNP array analysis was performed using Illumina InfiniumHD HumanCytoSNP-12 chip. All data were analysed by Illumina KaryoStudio and GenomeStudio software. RESULTS: SNP array analysis was performed in 108 fetuses (only 2 examination failures, 1.8%). In total, we detected CNV (copy number variation) in 29 samples (29/108 = 27%). 15% (16/108) of fetuses with abnormal ultrasound findings were found to carry clinically relevant CNV. Probably benign CNVs were found in 8 samples (8/108 = 7%) and in additional 5 CNVs parental samples have not been analysed yet. Excluding karyotypically abnormal cases clinically relevant CNVs were found in 10% of fetuses (9/94). In all cases with de novo chromosomal aberration the clinical relevancy was clarified (imbalances in 50%). CONCLUSION: Our data suggest that SNP array analysis is a relevant and useful technique in prenatal diagnosis.

[Autopsy and biopsy findings in disorders of mitochondrial beta-oxidation of fatty acids. Role of the pathologist in the diagnostic process]. / Pitevní a bioptické nálezy u poruch mitochondriální beta oxidace mastných kyselin. Role patologa v diagnostickém procesu.

Basic problems of the group of hereditary mitochondrial beta oxidation (BOX) disorders are presented with evaluation of the role of pathologists in the diagnostic process. The disorders manifest themselves clinically as usual by recurrent Reye-like episodes (acute hepatopathy and encephalopathy) typically in low age levels. Integral part of the clinical picture is often a myopathic symptomatology which at some cases may display even persisting character. The findings at the tissue level are dominated mostly by steatosis of the organ set with a high beta oxidation level (liver, heart, skeletal muscle, kidney) and toxic effects of the intermediate metabolic products of the derranged beta oxidation process. So far eighteen enzyme defects have been described affecting either transport of fatty acids across the mitochondrial membranes or their oxidative degradation at various levels, pointing to an absolute dependence of the final diagnosis on biochemical analysis. Pathologist's conclusion in cases dying without diagnosis is limited to suspicion of a BOX disorder only. However, pathologists can contribute significantly to unraveling and specification of the underlying BOX defect by collecting adequate samples of body fluids and of unfixed organs. Nevertheless, the validity of these samples, even if widely recognized, is limited. The best approach is to provide samples enabling to perform biochemical evaluation of the whole BOX process in integral mitochondrias. This requirement is fulfilled solely by establishing fibroblast tissue culture post mortem.